Yellow Jackets are a variety of wasp that have nests in the ground:
http://en.wikipedia.org/wiki/Yellowjacket
They are common in NH.
Paper Wasps normally have nests up under some structure like under an outdoor table or house eve. They have a dark brown articulated body, also common here.
http://www.extension.umn.edu/distrib...re/dg3732.html
Whitefaced hornets have large hanging nests, very nasty.
http://www.muenster.org/hornissensch.../baldfaced.htm
In any case wasp and hornet spray after dusk has always done it for me. You may have more than one nest or you sprayed the wrong hole as in maybe a chipmunk hole.
Be careful.